The new money is expected to be used in education
Tanzania has secured funding of about $1.1bn (£770m) from the World Bank,
International Monetary Fund (IMF) and other international donors.
The decision at the weekend followed a two-day meeting between government officials, donor country representatives and lending institutions.
The money, which is being provided in the form of low-interest loans and grants, will support projects such as water, health, education and agriculture.
Tanzania has become one of Africa's fastest growing economies, thanks to a series of reforms introduced by President Benjamin Mkapa since his election in 1995.
"The need is more but the amount is reasonable," Finance Minister Basil Mramba said of the weekend agreement.

President Benjamin Mkapa has pushed through several reforms
Tanzania has already signed up to HIPC, the Highly Indebted Poor Countries Initiative, securing about $2bn last year.
Fear had existed that the violence in Zanzibar during the elections last year and the row over the purchase of a new satellite navigation system had soured hitherto good relations with international donors.
Many donors see Tanzania as a much-needed success story and the fresh money is designed to prop up the government's economic reforms.
Since the election of President Mkapa, the Tanzanian government has managed to push through key economic reforms - including some state privatisations - which has enabled it to win favour.
African success story?
The economy has grown 5% to 6% since the 1990s, largely thanks to improved exports and increased foreign investment in mining and tourism, areas that had previously been declining.
It is expected to grow 5.9% this year, an improvement on growth of 4.9% seen last year.
With inflation now in single digits - having in recent years been close to 30% - IMF funds have also bolstered foreign exchange reserves to a comfortable level.
So far these economic improvements have not resulted in a higher standard of living for ordinary Tanzanians.
President Mkapa now stresses that poverty reduction is a priority, with the aim of the fresh money being to generate income and improve social welfare.